package 刷题;

import java.text.DecimalFormat;
import java.util.Scanner;

public class 三角形的面积 {
    public static void main(String[] args) {
        Scanner scanner=new Scanner(System.in);
        double a=scanner.nextDouble();
        double b=scanner.nextDouble();
        double c=scanner.nextDouble();
        double C = Math.toRadians(c);//将c转化为c度
        double S=(a*b*Math.sin(C))*0.5;
        DecimalFormat df=new DecimalFormat("0.00");//保留小数点后两位
        System.out.println(df.format(S));
    }
}
